Flash slouched on guard duty. Another week with the Princess of Friendship, Bearer of the Element of Magic, savior of Equestria, and here they were, still in the library, reorganizing it again. He could feel his brain cells committing suicide from boredom. He couldn't even turn his thoughts inward. If he did, he'd likely pop a boner while on guard duty.

He didn't want the princess getting the wrong idea.

Twilight stood above him on a ladder. The princess of friendship was wearing a long, black skirt. Still, one look above and you could see her blue, lacy panties digging into her purple flesh.

The princess was a whopper of a mare. All alicorns were and she was no exception. Small, wasp-like waist. D-Cups jiggling even in a stiff bra and nice hips, that gave her a mouth-watering hourglass figure that just screamed to be groped.

And she hid it behind a sweat-shirt and a long, black skirt...

Flash clenched his jaw, trying to keep his hormones in check. His golden guard's armor hid his body pretty well, but revealed his muscled arms from training and his legs that could run a marathon. Unfortunately for him, the metal covered up his crotch, meaning if he got hard, his 8'' penis would be crushed more than if it was in a chastity belt.

He looked up for a moment, checking on the princess only to get an eye full of panties. He could feel his cock stiffen as he forced himself to look away.

"Excuse me, Flash? Could you give me Calligriostos Calibrated Compendium from the third shelf?" asked the princess and pointed at a big book. In order to get it, Flash had to step onto the ladder. And get closer to the princess..

"Of course, Princess," he said through clenched teeth. He stepped on the lowest run of the ladder, taking them up one by one until he was on the one right below her. He reached over to grab the book, feeling his pecs touch the back of her leg though the armor.

He pulled the book over and held it up to her, getting a good bottom view of her voluptuous breasts.

"Thanks!" Twilight put the book in its proper place. It was quite interesting to see her lifting this big, heavy beast with just one arm. Again, alicorns. Flash surely had enough experience with them to expect that.

The princess then looked down, her beautiful face and big eyes entrancing her new guard. "I'm coming down now," she warned and stepped off the ladder.

On the ground she patted off her dusty clothes and sighed satisfied. "Okay, that’s ‘Section C’ done," she said and smiled at Flash. "I'm really glad you´re helping me with this. Spike is on vacation in the Dragonlands and I needed some help. I know, it's technically not your job, but thanks anyways."

"It's so convenient, that you were in Ponyville, when I put the job-offer up," she mused, before shrugging her shoulders. "Lucky, isn´t it?"

"Yeah. Lucky." Flash forced a smile on his face, trying not to dwell on what got him sent here in the first place. That mare was still probably selling herself since he didn't tell her to stop. He probably should head back to Canterlot to check up on her and see if her fellatio improved. "The Royal Guard lives to serve, Princess."

"It sure does." Twilight smiled at him. She then looked up her scroll. "Okay, so I think I can do the rest myself for now. I will call you for the ‘Section H’ later in about....three hours, so… you have some free time. Maybe you can read a book? Just put it back, where you got it, okay? And don´t go into the forbidden section. I´ve not yet renewed the sealing on that. Just keep away from the red bookshelves, okay?"

Twilight smiled and then walked away, her hips swaying naturally.

"Yes, ma'am!" He gave her a wing salute and waited for her to leave. "Books, books books." He felt sick. "I know you've spent the last four hours looking at them, but just go read another!" He started walking down to Section H, but overshot and ended in surrounded by red bookshelves. "Don't worry, it's just books. They're wonderful aren't they? Books, books books!" he continued to chant.

He stopped his mocking and looked around the bookshelves. The forbidden section. He was about to turn before he felt a book call out to him. Mind Magic and You: A Pegasi Guide, the side read. He felt compelled to grab it.

Taking it down, he noticed the author's name was scratched out. Shrugging, he opened it and found complex spellwork, runes, and circles that didn't require a horn to use. The glossary indicated spells and potions to make ponies smarter, dumber, more loyal, forgetful, etc. etc. etc..

Flash bit his lip, trying to hold back a grin. This was just what he needed. Something to help him get another mare to relieve himself. Perfe-- wait, what was that last one? He flipped to the page in question. In big letters at the top, it read "Alicorn Enslavement Circle."

His eyes went wide as his mind worked at 200 miles an hour as he read.

This circle can be used on a sleeping, unconscious, or awake alicorn. It'll last a full day, after which they will awaken back to their normal selves. During that day, they will be fully under the caster's control, doing whatever they ask. Danger: Do not pair this spellwork with ‘Aljura Configura’ in any way. The spells combined will kill the caster.

He skimmed the rest of it. This could work, if he chained the spellwork, but it was dangerous. If he slipped even once, he'd be a dead stallion.

He closed the book and set it in his saddle bag, rushing over to Section B to pick out a cover book and set both in his bags by the door

During his break, Flash spend quite some time skimming this forbidden book. He had a faint idea, how lucky he had been. If the seals had been on, he would have set off an alarm. If the book had been cursed, all manner of things could have happened to him. But, he had been lucky. Extraordinarily lucky.

The question was just, what now? He knew where Twilight was. He also knew where her laboratory was for any ingredients he might need. Smiling, a plan started to form in his mind, a red tint flashing in the back of his eyes.

Flash scrubbed at his eyes. Another four hours of watching books, another four hours of his life wasted. In the safety of his room, he looked over at his desk, where the restricted library's book lay open on what he called the first step: Perception blocking. He walked over to it, reading over the ingredients list again. Most of the stuff was simple, but he still needed a special crystal dust.

He closed and hid the book as best he could. He couldn't be too careful, so he hid it with his porn magazines in the magical locked chest he bought before leaving Canterlot. Stepping out into the dark, quiet castle, he made his way to Starlight Glimmer’s Lab. If anypony wouldn't have detailed records of her supplies, it'd be Starlight.

All residents of the castle were asleep at this point in the night. The only one, who would usually still be up would have been Spike, but he was away. So, Flash sneaked through the dark hallways. Cold crystal, so beautiful and bright on the day, now dim and black without light. The Castle of Friendship could get downright spooky under the right circumstances.

Flash came by Starlight’s room and a quick eavesdrop told him she was asleep. Same with Twilight, as he knew. Starlight’s lab was empty and open.

The lab was in the basement of the castle, away from all the important rooms and secured with a double-sealed obsidian door, covered in protective runes. Nopony could get in without knowing which runes to deactivate. And the combination was only known to the princess, her pupil, her assistant, her royal guard, her friends, the occasional college student who asked...

Yeah, Twilight wasn’t big on security, really...

As Flash entered the lab, he quickly switched on a light crystal. The room was littered with tables and all manner of strange devices. Whether it was a distillery, a glass-vault of sort or the big cage made out of diamonds in the back. A lot of the equipment was strange, expensive and probably dangerous.

But the most important thing was Starlight’s storage box. Outfitted as a simple closet, it had gotten a space-enhancement from a local expert to make it, as he said, "bigger on the inside". In there, Starlight stored all her ingredients and tools for her arcane experiments.

Flash walked over to the box, watching the floor. Starlight sometimes left wards and traps lying about, claiming it was to catch Trixie or wayward students. The last five emergencies included students being trapped in this very room, but not all were too bad. There was that rope trap that left all of Trixie's assets showing.

He shook his head, banishing the distracting thoughts. He tapped the door of the closet and pushed his hand in, thinking of the crystal dust. Pulling his hand out, unfortunately, brought only a bottle of strange liquid.

He shoved his hands in over and over again, pulling out an entire army of bottles, which he set on the counter. After the bottles came the bags of herbs. He formed a pile large, enough to cause even Tree Hugger to pass out. After those were out, he pulled out the container of the requisite crystal dust.

Flash stuffed the bottles back in followed by the herbs, checking the clock. He'd wasted so much time. If someone woke up, he'd be screwed!

The hallway was still dark. For some reason it felt a bit as if the walls were watching him. Twilight once said the castle was alive and had a will of its own. Probably a joke, though the were instances of people getting lost in the corridors and the layout changing for some inexplicable reason. Or they really needing to pee and suddenly standing in front of the bathroom, despite being on the other side of the castle.

Still, everything was quiet as Flash walked through the corridors with his bottle of dust.
As he came by Starlights room, a light switched on.

"Mr. Sentry...? Is that you?" asked a tired Starlight through the door.

Flash froze, stuffing the bottle into one of his pajama’s pockets.

"Yes, Magus Glimmer." He snapped off a salute. "I was checking on your lab. I thought I felt one of the wards go off."

It still bothered Flash that this mare had more authority than him. She wasn't a princess, nor a member of the guard. She shouldn't be able to order him around, but that was what Princess Twilight ordered of him

"Oh. Good. I felt that as well," mumbled the mare and the door opened. Starlight stood in her pajamas, blinking the sleep out of her eyes. She was certainly not bad looking. Not as much as a stunner as the princess, but that was a very high bar. Her C-Cups were nice and firm, she had attractively wide hips that accentuated her ass. This was a mare, that would do well with platform shoes and waving hips. Of course, if she weren’t a violent prude.

Given that she used to be a small-time dictator and brainwasher and once almost crashed the time-space continuum, it was a bit of a miracle that she was now Twilight Sparkle’s pupil. Then again, who better to look after a mad magus than the Element of Magic?

She yawned and put a hand on her hips, as she looked at Flash. "Found the culprit, guard?" she asked, like she would talk to a servant.

Flash clenched his teeth. "No, ma'am, though I did find some of the herbs on the counter, some bags opened. I put them back for you."

The mare got awake in a second. "Oh? Ohohoho, w-well, that’s good! Because they are very vital. Yes, very vital to the current project," she said quickly. She then nodded. "I-I well, you´re dismissed. Have a good night and, ehm, good night."
With that she quickly closed the door.

Flash dropped his salute, resisting the urge to spit at her door and started a quick jog back to his room. Opening the door, he all but ran over to his lockbox and brought out the book. He'd either have to get the spell prepared now or tomorrow. Considering the Princess was often needing him to stay later and later, there was only one choice.

Flash flipped the book to page 14: Perception blocking. According to the script that he read over a dozen times, it would allow a pony to go unseen and unnoticed by others around him. Its listed uses included exhibitionism, scouting, and general fun. However, there was one glaring flaw. Sex was off limits. If he had sex with a pony, they would instantly see him. He'd still be invisible to others, but he didn't want to get caught in the first place.

He brought out the dust, pouring some of it into a bowl. Next, the feather of a pegasus, followed quickly by the fluids of the caster. Spit or jizz would work, but considering he wanted to sleep soon, he picked the former. He mixed it for a few minutes before adding the last ingredient: an eye of newt. Every single room in the castle had a jar of eyes in it. Apparently, Twilight bought them in bulk, despite them having no actual magical properties in most spells.

Perception spells, however, always required eyes of newt.

Crushing the eye into the dust, he mixed the now liquid and poured it into a cup. All that was left was making the proper markings on his body when required. Feeling his own magic drain as he worked, he pushed himself from his desk and stumbled over to his bed. Laying on it, he passed out within seconds.

The book, still lying on his desk, flashed red before hiding itself in his lockbox.

Flash´s dreams were vivid and quite erratic. He heard voices and scenes flashed before his eyes. Breasts, naked flesh, the screaming moan of a mare and a dark laugh.

As his eyes opened on the next morning, he noticed a few things. First, he was on the ground, having fallen out of his bed in the night. Second, he was covered in sweat, as if he had taken a bath. And third he had a raging erection. His cock felt like it was about to burst out of his pajamas.

A quick look at the clock told him that it was six o’clock in the morning. Half an hour before the princess and her pupil woke up.

Flash's hands went straight for his cock, giving it a slight run over. He had an hour and a half, if that, to get himself off, take a shower, and show up for guard duty. He awkwardly shuffled over to his lockbox, smacking it open and digging around for his porn magazines. He brought them out, one after another, trying to find one that caught his eye.

None of them could hold his attention for more than a few seconds. Flat mares weren't enough. He needed more, he needed... he turned to the cup of perception blocking ink. Grabbing the book from the pile of magazines on the floor, he flipped it open to page 14 and frantically wrote the runes on his body.

It took him two tries to get it right. The first time only his upper half disappeared and the second time he accidently had messed up the thickness of the paint, so he flickered in and out of sight.

But finally he got it right and faded. Now, if everything went as the book promised he wouldn’t be able to be heard, smelled, seen or even be felt by anypony, as long as the contact wasn´t extensive or intrusive.

It was a bright morning and Flash Sentry could begin his first test drive of this magic.

He all but sprinted out of his rooms, heading straight for the princess' own. Streaking naked through a castle reminded him of his early cadet days and the ‘Ritual of Brotherhood’. He smiled, still remembering his prize that still lay with his brothers in Canterlot: A pair of Princess Celestia's panties and bra.

His dick stiffened at the reminder of the day he saw Princess Celestia in all her glory, her plump breasts begging to be sucked, her jiggling ass pleading to be slapped, her soaking pussy needing to be filled. He chided himself daily for his weakness, for leaving when he saw her like that.

He finally reached Twilight's rooms. He gulped, said a silent prayer to whatever god was out there, and entered.

The room was quite spacious. This wasn’t the first time Flash had entered her private room, but it certainly felt special. The princess had a few more "private" rooms, but those were usually reserved for reading, casting and so forth. Everything she wanted to do alone and not be disturbed. But this one was her sanctum. Here she went to let down her defenses and just relax. Here were all her private feelings and hobbies that weren’t for the public.

Flash went by her posters of Backstreet Colts and her bookshelf of "lesser" literature. Spike had gotten her to read comics and she had gotten a taste for some.
There was also a chest with her old stuffed animals. It wasn’t clear if it was for nostalgia's sake or if she still used them. Well, until now because Flash could see her nuzzling a stuffed elephant on her bed.

Speaking of her bed: It was enormous. A full on king-sized bed in royal style. Easely big enough to let four ponies sleep on it, with curtains that imitated the night-sky full with movement and comets streaking over the fabric.

And on it laid the princess in her blue pyjamas. She had never really bought new ones since her ascension, so they were a bit small. The fabric clung tight to her ass and hips and Flash was sure the button would pop off, if she breathed in hard enough.

Twilight was a big fan on continuuity. Even if she neglected shame for it sometimes. Then again, she probably wasn’t aware of the picture she gave with this.

"Hmm. Flash, please put the Herbal Encyclopedia for Old Mundus, 5th Edition on the second top shelf. Thank you," she mumbled in her sleep, hugging her elephant.

Flash's eyes drifted to her breasts straining to free themselves from the top. He reached his hand forward and, shaking, opened the button, freeing them.

Twilight tits popped out, even bouncing a bit. A wonderful bust, comparable with Princess of Lus- Love herself. Supple flesh, violet nipples and shiny, smooth skin.
The princess sighed, but didn’t wake up.

Flash bit his lip. Unable to restrain himself further, his hand started jackhammering, looking at the Princess and all the things he wanted to do to her. Images popped into his mind.

Those nipples pierced, a leash attached to them so he could pull her along. Her rooms changed completely. Instead of books and animals, it'd be toys. Instead of posters of bands, she'd have pictures of her new state in life. These rooms would belong to him, his own playplace.

He imagined Twilight giving him a special friendship lesson, sucking his cock every morning, giving her body every day, and riding him late into the night. He could see her happy face change to one contorted in pleasure, drooling over her own mattress.

He pumped faster, harder, images coming faster. Ignoring her library, her duty as a princess, satisfying only her own lust every day. A dildo stuck in her, ready to sneak into a bathroom if she needed to get off in public.

He was on the edge, he just needed a little more.

Twilight moaned. Not sexual, but quite close if one had the imagination.

"Hm. Yess. Give me all the pancakes, Spike. Put the caramel-sauce on them....sloooooooowlyyy..." she mumbled in her sleep and licked her supple lips.

That set him over the edge. Streams of cum exploded from him, hitting the princess' hair then her mouth. His jaw clenched, his head hung back, crying in pleasure, he covered her in his seed, expelling more in one go than he had in the past two weeks.

For a few tense seconds, the air stood still. Then, Twilight woke up.

"Yawn~, good morning," she said, cum dripping from her chin.

She smiled, drowsily stood up from her bed and opened the windows. She stretched her arms to the morning rays and cooed in satisfaction. And did, at no point, react to fact that she was covered head to toe in cum. Flash could see it clearly, but Twilight didn’t seem to notice the thick strands off gooey, white liquid dripping from her mane and tits.
She did see her naked breasts, though.

"Oh? Aww, again? I really need to buy new pyjamas," she said and buttoned it up. She walked happily to her closet and choose her wardrobe for the day. A black blouse and long, blue skirt down to her ankles. Dripping white jizz, all over them.

She walked to her door, opened it and went on towards the bathroom.

Seeing this, Flash's dick sprang up, ready for round two, but he already knew where to get a better sight. His eyes flicked to the bathroom door, seeing it was open. He snuck in and sat on one side, eagerly awaiting the show.

Sure enough, Twilight stood there. She stripped out of her tight and wet pyjamas. Due to their small size, she actually had to wiggle a bit and almost peel them off, which served as a nice almost-strip for Flash. Her bouncy ass shaking before him, as she got out of her pants.

Then, in all her naked glory, the princess stepped into the shower. The water came down and she soon washed herself. The jizz was washed away, but something far better was now happening.

Twilight caressed her sexy body with her long hands. She stroked over her skin, as it got wet and shiny under the light. Her long mane laid tight to her head and she gasped nicely under the hot water.

And then the lotion. She rubbed it all over her body. It didn’t foam, instead it was like oil and it gave her skin a permanent, luscious shine. A recommendation from Rarity. Finally, she stopped the water and stood in her shower, indulging in the dripping of her wet body and letting the oil seep into her wonderful skin.

Flash bared his teeth with a growl throughout the show, edging himself. He needed to hold off until the water was done, he needed to get her covered again. As she stood there, letting the oil sink in, he got up and pointed his hose of a cock directly at her. Aiming mainly for the face and tits this time, he exploded, sending another river of cum over her.

Twilight didn’t react, most likely because this load was a bit less thick than the last one. Instead she just sighed satisfied and stepped out of the shower.

Dripping of cum, she got a towel and rubbed herself dry. Getting the cum into the towel and off her body in the process, much to Flash’s disappointment.

She enveloped her messy mane with her magic and flash-dried it, before combing it back into her usual style. She wrapped a dry towel around her body and walked out of the bathroom and back into her bedroom.

Flash, coat slick with sweat and juices, followed Twilight out. He knew for a fact he'd need to get off again if he saw her wearing cumstained clothes, so he beat a hasty retreat back to his own shower.

He entered his room, noticing his magazines strewn about wildly, but one caught his eye. It was a magazine with a blank cover. Opening it up, he saw the first picture was of Twilight, asleep with her boobs hanging out of her shirt covered in his cum. He flipped through it, only to find the rest of the pages were blank.

He flipped back to the cover, now noticing a single note.

Nice work. I will continue watching. Here's a gift, freely given.

Somepony knocked on his door.

"Flash? Are you still sleeping?" asked Twilight from the outside. "There’s an emergency!"

Author's Note

Hey, everyone. Another story, yes, but I promise for those that care, it won't be taking over my other story, Changing Minds. Instead, this is a side project I'm writing with Nohen (again, check him out, link in description). I hope you enjoy it.

As always, criticism is welcome.

Next chapter should be out in the next few days.